OnQ Blog

Thanks to Snapdragon, LTE upload speeds are getting faster too

8 Jun 2016

Qualcomm products mentioned within this post are offered by Qualcomm Technologies, Inc. and/or its subsidiaries.

Since the launch of LTE networks in late 2010 and early 2011, LTE download speeds have gotten steadily faster. Upload speeds, on the other hand, have not improved one bit.

Until now.

Thanks to the Qualcomm Snapdragon 820 processor with X12 LTE, consumers in South Korea who have the LG G5 are the first in the world to enjoy these faster LTE upload speeds. And they’re not just a little bit faster—they’re way, way faster. In fact, thanks to a combination of technologies that we call Snapdragon Upload+, users of the LG G5 can experience upload speeds that are up to 3X as fast (compared to traditional LTE networks and phones without these technologies). It’s not often that a combination of technologies can provide such a drastic speed improvement.

This improvement to LTE upload speeds is long overdue. Much is said about growth of mobile traffic, but it’s usually focused on “downlink” traffic. There’s rarely a mention of the growth of uplink traffic volume, which has grown dramatically over the past several years.

People are sharing more photos and videos than ever, which have gotten larger in size and quality. Add to that the rise of live video broadcasting services like Periscope and Facebook Live. It’s only prudent that our LTE smartphones and networks adapt to this changing user behavior.

So what are the technologies in Snapdragon Upload+ that enable faster LTE upload speeds?

  • Uplink Carrier Aggregation (ULCA). The concept is identical to downlink carrier aggregation, but in the reverse direction. That is, the Snapdragon LTE modem inside the smartphone sends data to the cell tower on two LTE carrier frequencies simultaneously, resulting in up to 2X the LTE upload speed.
  • Higher order modulation, and specifically, 64-QAM. This is a signal processing technique whereby the Snapdragon LTE modem packs 50% more bits of data into every transmission to the tower. Instead of a single transmission carrying 4 bits of data, it carries 6 bits of data with 64-QAM. That results in an additional speed gain of up to 50% on top of the gains from uplink carrier aggregation. The typical LTE upload connection from a smartphone to an LTE network is capped at 50 Mbps peak (assuming a 20 MHz LTE carrier in FDD mode). ULCA doubles that to up to 100 Mbps, and the addition of 64-QAM boosts that further to a peak of 150 Mbps.
  • Uplink Data Compression (UDC). Snapdragon Upload+ features this unique third technology that supports even more uplink gains. It’s exclusive to Snapdragon LTE modems. With UDC, the Snapdragon LTE modem is engineered to compresses all uplink traffic, so that the same information can be uploaded with fewer bits from the phone to the tower. The idea behind UDC is to improve the efficiency of chatty traffic in the upload channel from things like text messages, and even HTTP web page requests. When that traffic is reduced, it opens up the channel for other users who want to upload pictures, videos, and other files, allowing them to complete their tasks faster. One significant downlink benefit is that UDC can actually help speed up web page loading too. Because all uplink text-based HTTP commands get compressed and sent to the receiving server faster, web pages can load up to 50% faster than without UDC.

The combination of the three technologies—uplink carrier aggregation, 64-QAM, and uplink data compression—in Snapdragon Upload+ can boost the peak upload speed in an LTE network from 50 Mbps to 150 Mbps in FDD networks. In TDD networks, which share the same LTE carrier for both uplink as well as downlink, peak speeds go from a modest 11 Mbps to a respectable 33 Mbps. That is an astonishing gain, and has tremendous and immediate impact on the user experience, as shown in the video above.

All three major LTE operators in South Korea—SK TelecomKorea Telecom, and LG U+—have commercially launched these new technologies on their networks, and thanks to Snapdragon, users with the LG G5 can enjoy them today. Other operators around the world are trialing or field-testing these technologies, including China Mobile, the world’s largest mobile operator.

Several phones other than the LG G5 are already providing this better LTE upload experience, including the LeEco Le Max Pro, the Asus ZenFone 3 Deluxe (both using the Snapdragon 820 processor with X12 LTE), and the China Mobile A2 (using the Snapdragon 617 processor with X8 LTE). The latter, at only 799 RMB retail price, shows the ability of Qualcomm Technologies to drive advanced technologies across product tiers, pushing the mobile experience forward for more users.

We are incredibly excited that Snapdragon Upload+ has successfully launched, and look forward to proliferating it to even more smartphones and LTE networks.